How can one pay zakat on inherited shares that have not had zakat paid on them for ten years, knowing that annual profits (money or shares) were received, and the shares were sold for 2250 Kuwaiti Dinars, and there is no information available regarding the number of shares or their market value in previous years?

Zakat (definition) must be paid for all past years, as it does not lapse with time, provided that the wealth reached the nisab (definition) and a full year passed over it. The number of shares and their value can be determined by reviewing the account statement with the company, and 2.5% of the capital and profits should be given. If the shares represent trade goods, then Zakat is due on both the capital and the profits. However, if they represent fixed assets and their income is intended, then Zakat is due only on the profits if they reach the nisab and a full year passes over them. But if the intention is to trade with them, then Zakat is due on the original shares and their profits. If it is not possible to know the exact number of shares for each year, an estimation based on probability and caution is preferable. The nisab for Zakat is the equivalent of 85 grams of gold or 595 grams of silver.